The project on polychlorinated environmental compounds will be continued using isomerically pure hydroxylated derivatives of PCB's, i.e. metabolic products of PCB's in order to further elucidate the structure - induction activity relationship. Disposition of different polychlorinated biphenyls in the organism will be investigated. The nature of UDPglucuronyltransferases and epoxide hydrase will be further studied with use of heavy metal salts in vitro. Also the effects of heavy metal salts in vivo will be elucidated. The investigations on the metabolism, and effects of styrene and styrene oxide will be concluded. The studies of benzo(a)pyrene metabolism in the everted intestinal sac will be contined by use of isolated intestinal loops in situ to further evaluate the significance of metabolism during the absorption process, as well as the significance of the intestinal metabolism as a protection of the rest of the organism. Effect of tabacco smoke on these phenomena will be investigated. The effects of smoking on the metabolism of vasoactive hormones in the lung will be studied, as well as on the lipoprotein lipase activity in the lungs. The factor in tobacco smoke responsible for the relaxation of smooth muscle will be characterized. Dietary factors regulating intestinal drug metabolizing enzyme activities will be elucidated; the effects of contaminant free brussels sprouts and cabbage on these enzymatic activities will be studied. The steroid metabolism in the gingiva from healthy males and females, as well as the metabolism in gingiva during inflammation and phenytoininduced hyperplacia will be further elucidated.